{ INFORMATICS.MCCME.RU
  Problem statement: http://informatics.mccme.ru/moodle/mod/statements/view3.php?chapterid=3171
  Verdict: Accepted
}
uses SysUtils, Math;
 
const
	firstV:int64=round(1e12);
 
var
	k,kk,ls,cc:int64;
	s:string;
	i,j:longint;
	a:array[0..100010] of int64;
	f:boolean;
 
begin
reset(input,'input.txt');
rewrite(output,'output.txt');
readln(s);
cc:=0;
ls:=length(s);
while ls>0 do begin
	kk:=pos(' ',s);
	if kk=0 then begin
		k:=strtoint(s);
		s:='';
	end else begin
		k:=strtoint(copy(s,1,kk-1));
		delete(s,1,kk);
	end;
	ls:=length(S);  
	inc(cc);
	a[cc]:=k;
end;
for i:=1 to cc do begin
	f:=true;
	for j:=1 to cc do
		if (i<>j) and (a[i]=a[j]) then begin
			f:=false;
			break;
		end;
	if f then write(a[i],' ');
end;
end.